Control mechanism



Nov. 11, 1941. w. H. SMITH CONTROL MECHANISM Filed Nov. 12

aammuzatiflg Winding 'ampr'essbr D Gil/[072 INVENTOR WaZzer/i Sm 2272.

ATTORNEY Patented Nov. 11,1941

CONTROL MECHANISM Walter H. Smith, Wilkinsburg, Pa., assignor toWestinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., acorporation of Pennsylvania Application November 12, 1938, Serial No.239,931

14 Claims.

My invention relates to control mechanism and it has particular relationto reverse-directionresponsive controlling mechanism associated with adirect-current dynamo-electric machine and a storage battery on arailroad-car or other transportation-device. More specifically, myinvention vielates to apparatus for conditioning the air in passengervehicles or for cooling commodities in other vehicles, particularlyvehicles of the railroad type, although my invention is not .limited tosuch uses.

One object of my invention relates to the provision of a so-calleddrag-relay characterized by having two pairs of contact-members, foreach direction of movement, the contact-members of each pair beingactuatable in responsive to different amounts of displacement of thedrag-relay.

A further object of my invention relates to the provision of adistance-responsive relay comprising a pair of cam-actuated pivotedarms, with suitable means for holding and releasing the arms. I

With the foregoing and other objects in view, my invention consists inthe methods, systems,

combinations and apparatus hereinafter described and claimed, andillustrated in the accmpanying drawing, in which the single figure is adiagrammatic view of circuits and apparatus embcdying my invention andillustrating the principles thereof.

The drawing shows my control mechanism in a form adapted for applicationto a railroad car having a car-axle I which is provided with agear-drive 2 for driving an axle-driven shaft 3.

The illustrated mechanism is utilized in connecswitch H, to positive andnegative buses and i The equipment further includes a direct-curlentdynamo-electric machine l2 which is use- 'ab e either as a generator forcharging the battery ill, or as a battery-energized motor for drivingthe compressor 4 through a mechanical driving- I, when theunloaderconnection, such as the belts II. The electric machine I2 isprovided with a field-winding l4 and a commutating winding IS, thelatter being connected in series with the armature-circuit I6, oneterminal of which is permanently connected to the negativebattery-terminal and the other terminal of which is controlled inaccordance, with my invention.

The illustrated equipment further includes a speed-responsive,engageable and disengageable,

mechanical driving-means, illustrated in the form of a centrifugalclutch IT, for mechanically connecting the axle-driven shaft 3 to thecompressor 4 and to the electric machine 12 at car-speeds above apredetermined speed, such as 12 miles per hour, and for disconnectingthe same at lower speeds.

In accordance with my invention, I provide a so-called drag-relay l8,and a so-called distancerelay I9, both of which are controlled, forconvenience in installation, from an auxiliary shaft 2| which ismechanically connected, through a belt-drive 22, to the axle-drivenshaft 3. Both the drag-relay l8 .and the distance-relay [9 are ofspecial construction, which will now be described.

The drag-relay l8 acts as a reversing-switch means for responding tomovement of the caraxle l, and it comprises a reversibly movable disc orother switching member 23, having biasing means, in the form of two setsof springs 24 and 25, for restoring the disc 23 to a neutral centralposition. The biasing springs 24 and 25 are pro vided, as illustrated,with means, such as stops 26, for increasing the effectiveness of thesprings at a predetermined displacement ofthe disc 23 from its neutralposition, in order to provide a first tilting-range in which the disc 23is easily tiltable, in either direction, and a second tiltin.,- range inwhich it is necessary to exert a larger tilting-force per unitdisplacement of the disc 23.

The tiltable disc 23 of the drag-relay l8 carries four inclinedmercury-switches 21, 28, 29 and 30, or equivalent tilt-responsivecontactmechanisms. These four mercury-switches '21 to are arranged inpairs,one pair 21 and 28 being actuatable in response to forwardmovement of the car-axle I, and the other pair 29 and 20 beingactuatable in response to backward movement of the car-axle I. The firstmercuryswitches 21 and 29 of the respective-pairs are just slightlytilted, and thus they are arranged to be sensitively responsive to veryslight displacements or tiltings of the switch-carrying disc 23,

and they are so arranged that their electrical con 'tacts are brokenwhen said mercury-switches 21 and 29 are actuated in response to thetilting of the disc 23. The second mercury-switches 28 and magnet 33 iscarried by the auxiliary shaft 2|,

while the drag-disc 32 is carried by a shaft 34 which is connected tothe tilting disc 23. When torque is applied to the magnet 33, a veryslight movement of the magnet with respect to its associated drag-disc32 causes suflicient eddy currents in the drag-disc to establish asensible torque in the shaft 34, tending to tilt the switch-carryingdisc 23 in the same direction of rotation as the magnet 33. As the slipbetween the magnet 33 and the drag-disc 32 increases, the electricaltorque also increases, up to a point determined by the design of theapparatus.

My distance-relay |9 is designed to detect movement in the auxiliaryshaft 2| which, in turn, moves with the car-axle I, and it comprises apair of arms 36 and 31, pivoted at 38 and 39, normally drawn towardseach other by means of a spring 4|, and actuatable away from each otherby means of a cam 42 carried by the auxiliary shaft 2|. Each of thepivoted arms 36 and 31 carries two front or make contacts 43 and 44, andone back-contact 45, the make-contacts being closed whenthe respectivearms are actuated, and the back-contacts being closed when therespective arms are in their normal non-actuated positions. Therespective arms 36 and 31 are also provided with arm-holding means,illustrated in the form of magnet-coils 46, which are capable ofretaining their respective arms in their actuated positions.

Associated with the steeply tilted mercuryswitches 28 and 38 of thedrag-relay I8, is a reversing relay 48 of a well known type, which isprovided with a forward electromagnetic switching element 49 and abackward electromagnetic switching element 58, the two switchingelements being mechanically connected together by means of a tiltinglever 5|, so that when one of the switching elements is closed, theother is open. The operating coil of the forward" switching element 49is energized by the closure of the forward mercury-switch 28, while theoperating coil of the backward switching element 58 is energized whenthe backward mercury-switch 38 is actuated to close its contacts. I

The reversing-switch elements 49 and 58 are each provided with a firstmake-contact 53 which serves to connect a control-circuit bus 54 to thepositive battery-terminal when either one of the steeply tiltedmercury-switches 28 or 38 is actuated to its closed position.

Each oi the reversing-switch elements 49 and 58 is also provided with asecond make-contact 55 for connecting the negative battery-terminal toeither terminal 56 or 51 of the field-winding'l4, depending upon theposition of the reversing-switch mechanism 48. Each of thereversing-switch elements 49 and 58 is also provided thereversing-switch mechanism 48.

The auxiliary switching bus 54 serves, among other things, to energizethe operating coil or a so-called field-transfer switch 6|, which isprovided with a back-contact 62 and a front or make-contact 63. Thus,when the auxiliary relaying bus 54 and the field-transfer relay 6| aredeenergized, that is, when the steeply tilted mercury-switches 28 and 38are in their non-actuated positions, the back-contact 62 of thefield-transfer relay 6| is closed, so as to partially make a motoring"field-energizing circuit which may be traced, for the present, from aconductor 54, through the back-contact 62, to two serially connectedresistors 65 and 68, and thence to the fieldenergizing circuit 59. Whenthe field-transfer switch 6| is energized, however, as a result of theactuation of either one of the mercury-switches 28 or 38, the motoringfield-circuit is broken at the back-contact 62, while the make-contact63 of the relay is closed, thus energizing a generating field-circuitextending from the positive battery-terminal through a carbon-pilerheostatic voltage-regulator .61, and the makecontact 63, and thence tothe field-energizing circuit 59.

The auxiliary control-circuit 54, which is energized from the positivebus wheneither one of the steeply tilted mercury-switches 28 or 38 isactuated, is also utilized in the control of the generating operation ofthe electric machine l2, and for this purpose, it is connected in serieswith the usual generating contact I8 of a reverse-current relay II,which may be of usual construction, and which is illustrated as having apolarizing winding 12 energized from the storagebattery terminals andand two actuating windings I3 and 14. The actuating winding '13 is acurrent-winding which is illustrated as being connected across a shuntI5 in the armature-circuit 6 of the dynamo-electric machine l2. Theother actuating winding 14 is a voltagewinding which is connected so asto be responsive to the voltage-difierence between the battery 8 and thearmature-circuit |6 of the dynamo-electric machine 2, as will besubsequently described. In accordance with my invention, thereverse-current relay 1| is provided with an extra back-contact 18,which is not usually provided on such relays, but which I utilize as anextra safeguard in controlling the motoring operation of the electricmachine l2, as will be subsequently described.

The first-mentioned make-contact ll of the reverse-current relay 1|, isutilizedto connect the auxiliary switching bus '54 to a starting-bus 88which is utilized for starting the dynamo-electric machine |2 in amannerwhichwill be subsequently described. The starting circuit whichtraces back from the starting bus 88, through the reverse-currentrelay-contact l8, and the auxiliary switching bus 54, to'one or theother of the steeply tilted mercury-switches 28 and 38, is utilized incontrolling the operation of the dynamo,- electric machine l2 as agenerator.

I also provide means for controlling the start 'ing circuit 88 duringthe operation-of the dynaand this which starts to the left of the'drag-relay-l8, at

the positive battery-terminal and thence passes through a thermostaticswitch 8| to an auxiliary motoring circuit 82. The thermostatic switch8| is utilized to close its contacts when it is desirable to operate thecompressor 4 to produce more cooling. and to open its contacts when nomore cooling is needed. The motoring circuit 82 is connected in serieswith the two back-contacts 45 of the distance-relay I8, and thence to anauxiliary motoring circuit 88. The two backcontacts 45 of thedistance-relay I8 are connected in parallel with each other, so that theauxiliary motoring circuit 83 is energized whenever either one of theback-contacts 45 is closed, that is, whenever either one of the pivotedarms 38 and 81 is in its normal non-actuated position, provided, 01'course, that the thermostatic switchcontacts 8| are closed.

It is necessary, now to describe the connections of the distance-switchI8, whereby the opening and closing of the back-contacts 45 arecontrolled. Each of the holding-magnets 48, for holding the respectivearms 88 and 81 in their actuated positions, is connected, through itsassociated front-contact 44, in an energizing circuit including anormally'closed contact 84 of a thermal relay 85. The thermal relay 85is provided with a heater-element 88 which is enerafter the tiltableswitch-carrying disc 28 of the drag-relay returns to its normal neutralposition, as the railroad-car approaches its condition of standstillafter having been moving in either direction.

Picking up the thread of the motoring circuit which has been traced fromthe positive battery- 'terminal through the thermostatic switch 8|, themotoring circuit 82, and the distancerelay back-contacts 45, to theauxiliary motoring circuit 88, it will be noted that this auxiliarymotoring circuit 88 is next connected in series with a make-contact 88of a low-voltage cut-out relay 88, and thence through the "motoring"back-contacts 18 of the reverse-current relay II,

to the previously-mentioned starting" circuit 88. The low-voltagecut-out relay 88 will be subsequently described.

The "starting" circuit 88, when energized either through the generating"circuit starting with one or the other of the steeply tiltedmercuryswitches 28 or 88, or through the "motoring" circuit startingwith the thermostatic switch 8|, is utilized to energize a train ofrelays 8|, 82, 83 and 84, which together constitute the startingmechanism for my dynamo-electric machine l2. The first relay 8| of thistrain is first energized from the starting circuit 88, through abackcontact 85 of the third relay 88. The first relay 8|thereuponinstantly picks up and closes its make-contact 88 whichinstantly energizes the second relay 82, causing the latter to instantlypick-up and close its make-contacts 81 and 88, which instantly energizethe third and fourth relays 88 and 84, respectively. The actuation ofthe third relay 88 closes its make-contact I88,

Ill

which 'energizes the main armature-circuit l8 of the dynamo-electricmachine I2 by connecting the same in a circuit which is traced from thepositive battery-terminal through the starting relay-contact I88, thencethrough the shunt I5, and thence through a starting resistor I 8|, tothe current-coil I82 of the rheostatic regulator 81, and thence throughthe commutating winding I5 to the armature oi the dynamo-electricmachine, the other terminal oi which ispermanently connected to thenegative bus The first, second and fourth starting relays 8|, 82 and 84are of a type having an instantaneous pick-up and a slow drop-out of,say, two seconds, as is symbolized by the dashpots I84. The thirdstarting relay 88 is the main line-contactor, having the mainline-switch III as previously described, and it locks'itsel! in, asindicated, through a holding-circuit make-contact I85, so that itthereafter stays "in as long as the "starting" circuit 88 is energized,regardless of the position of the second starting relay 92.

The first and fourth starting relays 8| and 84 are provided withmake-contacts I88 and I81, respectively, which are utilized toshort-circuit the motoring" field-resistors 88 and 88, respectively. Thesecond starting relay 82 has a backcontact I88 which is utilized toshort-circuit the armature-circuit starting-resistor I 8 I As soon asthe main line-contactor 88 picks up, it opens its back-contact 88 anddeenergizes the first starting-relay 8| causing the latter to start todrop out in a time, such as two seconds, determined by its dashpot I84.When the first starting-relay 8| completes its drop-out movement, itopens its make-contacts I 88 and 88, thereby inserting thefield-resistance 88 in the motoring" field-circuit, and deenergizing thesecond starting relay 82, causing the latter to start to drop out. in atime, such as two seconds, determined by its dashpot I84. When thesecond starting-relay 82 completes its drop-out motion,

it closes its back-contact I88 and opens its frontcontact 88, thuscutting out the armature-circuit starting-resistance IM and deenergizingthe fourth starting relay 84, causing the latter to start to drop out ina time, such as two seconds, controlled by its dashpot I 84. When thefourth starting relay 84 completes its drop-out movement, it opens itsmake-contact I81 and thereby inserts the field resistor 88 in the"motoring" field-circuit.

The voltage-coil 14 of the reverse-current relay II is connected acrossthe main contact I88 of the main line-switch 82. I

The carbon-pile voltage-regulator 81 which is utilized in thegenerating" field-circuit is provided with a voltage-winding 8 which isresponsive to the voltage of the dynamo-electric I machine I2,

The unloader relay 8 which is associated with the compressor 4, isenergized from the motoring circuit 82, which is energized whenever thethermostatic switch 8| is closed, calling for more cooling.

The low-voltage cut-out relay 88 compriseses- ..sentially a voltage-coilI I2 which is normally connected in shunt across the battery terminalsand through a resistor I I3 and a makecontact I on the mainl-ine-contactor 88 of the "starting mechanism. Thi low-voltage relay 88also normally holds itself ,in through its own make-contact 8 whichbypasses the make-contact N4 of the starting-relay 88. The function I ofthe battery as a result of prolonged operation of the compressor 4 fromthe battery, the low-voltage cut-out relay 89 being provided in order tomake sure that enough battery-capacity will always be left to take careof lighting, ventilating, and other necessary requirements.

In order to prevent the low-voltage cut-outrelay 89 from dropping out,on the momentary dip in voltage resulting from the large currentinrushwhen starting the electric machine I2 as a motor, a weak series coil H8is provided on the same magnetic circuit as the voltage-coil H2, andenergized from the current-shunt I5, in such direction and amount, as togive the voltagecoil II2 a sufficient boost during the startingcurrentinrush when the motoring operation is first initiated.

In order to be able to start the compressor 4 when the car is, standingin a switching yard, after a period of non-use with the mainbatteryswitch I'I open, I have provided, in association with theresistor II3 of the cut-out relay 89, a

starting push-button II8, which may be depressed, to pick up the cut-outrelay 89, after the main battery-switch 'II has been closed, if thebattery-voltage is over 70% of its normal strength. The push-button H8is preferably arranged to momentarily energize the cut-out relay 89'through only a portion of its series resistance II3. After the cut-outrelay 89 has once picked up, it will seal itself in, through itsmake-contact I I5, and its operating coil I I2 will receive enoughcurrent, through all of the resistance II3, to

- hold the relay in its closed position.

The operation of the mechanism is as follows. Referring to thegenerating operation of the electric machine I2, when the car startsinto operation and attains a suitable speed for operating the compressor4, such speed being perhaps of the order of 12 miles per hour, thecentrifugal thus setting up the field-reversing relay 48 in 1 the properpolarity depending upon the direction of car-travel. For convenience invisual-, izing the phenomena, it may be assumed that the mercury-switch28 or 38 closes when the car attains a speed of 12 miles per hour, thesame as the operating speed for the centrifugal clutch II, althoughthese two operating speeds need not be identical with each other. Whenthe me!- cury-switch 28 or 38 closes, it also energizes thefield-transfer relay 8|, thus braking the "motoring field circuit at 82and establishing a generating" field circuit at 83, withmaximun'figencrating" field-strength in the field circuit.

When the car attains a speed, such as 25 miles per hour, at which' thegenerator-voltage is slightly in excess of the battery-voltage, thereverse-current relay-contact I8 closes, under the influence of itsvoltage-coil I4, thus instantly energizing the starting relays 9| to 94,so that the main line-contactor starting-relay 93 will pick up and closeits main-contact I88, completing thearmature-circuit I8 of thegenerator, and causing the generator to thereupon charge the storagebattery I8. The reverse-current relay II then holds itself closed underthe influence of its current-coil I3. It will be noted that thearmature-resistance I8I is in circuit with the generator for a verybrief .time, until the second starting-relay 92 drops out and closes itsbackcontact I88. When the car-speed drops back to a'value below whichthe generator can no longer charge the battery I8, the reverse-currentrelay II drops out, opening its contact I8, thus deenergizing the mainline-contactor 93, and opening the generator armature-circuit I8 at I88.

When the car is standing still, the dynamoelectric machine I2 isoperable as a motor, driving the compressor 4 from the storage batteryI8, under the control of the thermostatic switch 8|. It will beremembered that the centrifugal clutch II is open, under theseconditions, so that the mechanical driving-connection I3, which exit isimpossible for the cam 42 to be actuating,

or pushing out, both of the pivoted arms 38 and 31. Hence, atstandstill, at least one of the pivoted arms 38 or 31 is bound to be inits normal non-actuated position, as controlled by the biasing spring4|, and it is possible that both of the pivoted arms 38 and 3.1 may bein their normal non-actuated positions, as illustrated.

Under the circumstances just described, the

auxiliary motoring circuit 83 is energized, through one or both of thedistance-relay contacts 45, and through the motoring circuit 82 which isunder the direct control of the thermostatic switch 8I. Since thelow-voltage cut-out relay 89 is normally energized, its contact, 88, inthe motoring control circuit, is closed. Since the reverse-currentswitch II is in its deenergized position, its "motoring contact I8 isalso closed. An energizing circuit is thus completed from the auxiliarymotoring circuit 83, through the contacts 88 and I8, to the startingcontrol-circuit bus 88, which serves to start the motor by energizing(by way of relays 9| and 92) the main line-contactor 93, and completingthe motoring circuit at the contact I88, thus connecting the motorarmature-circuit I8 across the storage battery I8, in series with thestarting armatureresistance |8|.-

The motor starts, with full motoring fieldstrength, through a portion ofthe motor-armature circuit I8, starting with the positivebattery-terminal at the main line-contactor relay-contact I 88, andcontinuing on through the shunt I5 to the field-circuit,,conductor 84,and thence through the normally closed backcontact 82 of thfield-transfer relay 8|, and thence through the starting-relay contactsI88 and I8! which short-circuit the field-resistors and 88.v Thefield-circuit thereupon continues, through the conductor 59, andthroughassasvs at one of the relay-contacts ll of the field reversing relay 44.

'Ihe motor l2 thus starts up, driving the compress? 4. At two-secondintervals after the initial energisation of the motor. the first, secondand fourth starting switches ll, 02 and 44 drop out, thereby' firstcutting in the fieldresistor ll, second cutting out the armatureresistorill, and third cutting in the fieldresistor 04, which places thefield-circuit in its normal motoring condition.

The motor continues to operate, until the starting" circuit 44 isinterrupted, as at one of the contacts 4|, 4| and I4.

When the car starts to move, the cam 42 of the distance-relay itimmediately starts to move with the car-axle I. The arm-holding magnets4| of the distance-relay ll are ready to be energiaed as soon as theirrespective associated make-contacts 44 are closed, the magnet-energizingcircuit being completed through the normally closed back-contacts l4 ofthe thermal time-delay relay II. The initial movement of the cam 42 thusresults in actuating first-one and then the other of the two pivotedarms II and 21, and each arm, as it reaches its actuated position,energizes its associated holding-magnet 48 and holds itself in itsactuated position. so that the cam 42 will no longer strike that arm, asthe cam continues to rotate. It will thus be evident that, before thecam 42 has'made a com.- plete rotation, both of the pivoted arms ll and81 will be locked in their actuated positions, with their back-contacts45 open, so that the motoring control-circuit is opened at 45, eventhough the thermostatic switch ll is closed, still calling for morecooling. It will be noted that this response of the distance-relay If,in opening the motoring control-circuit at 4|, will be made, at theearliest possible moment, in response to an extremely short distance oftravel, and vregardless of the speed of the car, which will benegligible at this point.

At the time when the back-contacts 45 of the distance-relay [9 open, thecar may not have moved sufficiently to open either one of the slightlytilted mercury-switches 21 and 29 of the drag-relay disc 22, so that, ifthe thermostatic switch ll still has its contacts closed, calling forcooling, a circuit will be completed from the positive battery-terminalthrough the thermostatic switch II, the mercury-switches 29 and 21, thetwo front-contacts 42 of the distancerelay is, and the heating-elementI! of the thermal time-delay relay 85, as soon as both of the pivotedarms 26 and 31 are moved to their actuated pomtions. If thisenergization of the thermal time-delay relay I! should continue for thetime-delay relay II to continue to be energized for anything approachingten seconds, unless the railroad car immediately stops after the veryslight motion necessary to open 'both contactsbecause theslightly-tilted mercury-switch 21 or 2!, depending upon the direction ofrotation,

is very sensitive in its response, and will respond moving to itsactuated position, opening its,

the car continues to sensibly move, very slow speed less than half of aper hour, after having moved far enough to open both back-contacts 44.As soon as one of the mercury-switches 21 or 20 opens, it deenergisesthe thermal relay 44, thus preventing an opening of the thermal-relaycontact 84, so that the arm-holding magnets 40 continue to remainenergised, holding the pivoted arms It and 21 out of contact withthe cam42, as the latter continues to rotate with the rotation of the caraxleI.

As the car continues to accelerate, it will finally reach-the speed,such as 12 miles per hour, at which the centrifugal clutch I! willengage, thus driving the compressor 4, and if the thermostatic switch Iiis still closed, calling for more cooling, the unloader relay I will beenergized, thus causing the unloader-valve I to be in a closed position,shutting on the direct communication between the discharge-pipe U andthe suction-pipe i of the compressor, so that the compressor will beloaded, performing the function of driving the refrigerant through therefrkerating equipment (not shown) which isconnectedtothepipeslandtinamanner' which is readily understood.

If, while the centrifugal clutch i! is engaged, the thermostatic switchOI should open its contacts, signifying that no more cooling is needed,the unloader-relay 4 will be deenergized, causing the unloader-valve Ito return to its normal open position, so that the refrigerant freelycirculates through the valv 1, without sensible load upon the compressor4, instead of passing through the refrigerating equipment as in thenormal operation of the compressor.

When the speed of the car again drops below the operating point of thecentrifugal switch l1, which may be something of the order of 12 milesper hour, the compressor 4 is again disengaged from the car-axle I, sothat it becomes. for the time being, impossible for the compressor 4 tobe driven, so as to obtain cooling, even though the thermostatic switchII is closed, demanding more cooling.

When the car-speed reaches a very low value, which may be considerablyless than one-half of a mile per hour, the drag-magnet disc 23 returnsto its normal neutral position, so that both of the slightly tiltedmercury-switches 21 and 29 are closed. A circuit will then be completed,assuming that the thermostatic switch 8| is still closed, through thesetwo mercury-switches 21 and 20, and through the make-contacts 43 of thetwo pivoted arms 38 and I! which are both being held in their actuatedpositions, so that the heating element 80 of the thermal time-delayrelay II becomes energized. Ina predetermined time thereafter, such as10 seconds, depending upon the operating constants of the timing relayIt, the relay-contacts 84 open, thus deenergizing both of theholding-magnets 4i, and permitting both of the pivoted arms ll and 21 toreturn to their normal, non-actuated position, unless one of said armsmay be held open by reason of the fact that the cam 42 might have cometo rest underneath said arm. The timing-switch delay of 10 seconds isdesigned to be so long that, even though the car was slightly moving atthe point when the drag-relay switches 21 and 2! were both closed, thecar will have had more thanample time to come to a complete standstill,before either one or both of the pivoted arms I! and I! are permitted toreturn to their normal non-actuated positions in which they will closetheir back-contacts ll and energize the auxiliary motoringcontrol-circuit 08, provided that the thermostatic switch II is stillcalling for more ceefing The time-delay of 10 seconds. more or less,introduced by the timing-relay II, is particularly useful when therailroad-car is quickly brought to a stop, and instantly reversed, asfrequently occurs when it is being driven by a switching engine. Underthese circumstances, the 10- second time-delay prevents an undesiredmomentary starting of the electric machine I! as a motor driving thecompressor 4. If the motor had been permitted to momentarily start up,driving the compressor 4 in the same direction in which the car hadfirst been travelling, which is the function of the field-reversingswitch ll, then when the car suddenly reversed its direction of travel.and very quickly accelerated in the reverse direction, it might attain aspeed of 12 miles per hour, sudicient to close the centrifugal clutchI1, before the compressor 4 had had time to come to a complete stop,thus subjecting the mechanical drive-mechanism to the strain of beingrequired to first bring the compressor to standstill before it would bepossible to start it up in the reverse direction.

It will be understood, of course, that any suitable braking means may beassociated with the motor I! for quickly atom) the same whenever it iselectrically deenergised after a motoring operation. As such means arewell known, I have not complicated my drawing by attempting toillustrate the same.

It will thus be seen that, between standstill and approximately 12 milesper hour of the rail; road-car, or whatever other speed of operation isinherent in the speed-responsive clutch II, it is While I haveillustrated my invention, am explained its mode of operation, inconnection with a preferred form of embodiment, I desin it to beunderstood that such illustration and explanation are only by way ofexample. as mam changes, in the way of omisions, additions, andsubstitutions, may be made by those skilled in the art without departingfrom all of the essential features of my invention. I desire, therefore,that the appended claims shall be accorded the broadest constructionconsistent with their language and the prior art.

I claim as my invention:

1. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising electrical driviug-means for drivingsaid mechanical load device when the transportationdevice is stationary,mechanical driving-means motivated by the movement of thetransportation-device for driving said mechanical load device when thetransportation-device is moving, movement-responsive means responsive toa predetermnied short distance of travel from standstill, substantiallyregardless of speed, for insur ing a deenergisation of the electricaldrivingmeans when the transportation device begins to move, andtime-delayed means, operative independently of the speed of themechanical load device, for delayedly resetting said movementresponsivemeans to its non-responsive position after a cessation of movement ofthe transportation-device.

muechanismfordrivingamechanicalload device on a movabletransportation-device, comprising eleetrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidimpossible to obtain cooling, by means of the compressor I. This is nota disadvantage, however, because passenger cars, and in general, othertransportation-devices, do not operate, for any material length of time,at very low speeds. Thus, passenger trains commonly accelerate anddecelerate at the rate of one mile per hour per second, so that thecompressor I would be out of commission, on such a train, for a maximumperiod of 12 seconds, which would be altogether negligible.

I have shown an alternative connection, associated with the auxiliarymotoring controlcircuit N, in the form of a two-position switch iii. Inthe full-line position of the switch lli, the motoring" control-circuitconnections are as previously indicated. with the "starting bus OIconnected. through the relay-contacts II and 80, to the auxiliarymotoring circuit 08, and thence through either'back-contact ll ofthedistance-relay II, to the thermostatic switch Ii. If thistwo-position switch iii is moved to its dotted-line position, the"starting circuit I. is connected, through the relay-contacts It and IIand the switch ill, to an auxiliary circuit III, which is energizedthrough the two slightly tilted mercury-switches 21 and ll, and thenceto the thermostatic switch Ii. Under these conditions, the starting andstopping of the motoring operation of the dynamo-electric machine I! isdirect- 1y under the control of the drag-relay mercuryswitches 21 and2!; and the distance-relay II is not utilised at all. The operation ofthese mercurs-switches 21 and flhasalreadybeenfully described.

mechanical load device, said electrical and mechanical driving-meansbeing each eifectively operative only upon the fulilllment of certainpredetermined conditions, speed-responsive means responsive to the speedof the transportationdevice. said speed-responsive means being operativeinresponse to increasing speeds of the transportation-device forfulfilling a condition necessary to the functioning of the mechanicaldriving-means in response to a transportation-device speed above apredetermined value, said speedresponsive means being operative inresponse'to decreasing speeds of the transportation-device for insuringthat the aforesaid mechanical driving-means is substantially inoperativein response to a transportation-device speed below a predeterminedvalue, means so interrelatedto the decreasing-speed response of saidspeed-responsive means as to be operative only sullequently thereto inresponse to decreasing spade of the transportation-device for fulfillinga condition necessary to the functioning of "the electricaldriving-means, movement-responsive means for insuring a deenergisatiohof the electrical driving-means when the-transportation, devicebarelybegins tov move-and time-delayed means, operative independently orthe speeds! the mechanical load device, for rel'ayedly resetting saidmovement-responsive mans to its nonrespomive position after a cessationof movement of the transportation-device.

3. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising electrical driving-means for at timesdrivim said mechanical. load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each effectively operative only upon the fulfillment of certainpredetermined conditions, speed-responsive means responsive to the speedof the transportation-device, said speed-responsive means beingoperative in response to increasing speeds ofthe transportation-devicefor fulfilling a condition necessary to the functioning of themechanical driving-means in response to a transportationdevice speedabove a predetermined value, said speed-responsive means being operativein response to decreasing speeds of the transportation-device forinsuring that the aforesaid mechanical driving-means is substantiallyinoperative in response to a transportation-device speed below apredetermined value, means so interre-' lated to the decreasing-speedresponse of said speed-responsive means as to be operative onlysubsequently thereto in response to decreasing speeds of thetransportation-device for fulfilling a condition necessary to thefunctioning of the electrical driving-means, movement-responsive meansresponsive to a predetermined short distance of travel from standstill,substantially regardless of speed, for insuring a deenergization of theelectrical driving-means when the transportation-device begins to move,and time-delayed means, operative independently of the speed of themechanical load device, for delayedly resetting said movement-responsivemeans to its non-responsive position after a cessation of movement ofthe transportation-device.

4. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising electrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each effectively operative only upon the fulfillment of certainpredetermined conditions, speed-responsive means responsive to the speedof the transportation-device, said speed-responsive means beingoperative in response to increasing speeds of the transportation-devicefor fulfilling a condition necessary to the functioning of themechanical driving-means in response to a transportationdevice speedabove a predetermined value, said speed-responsive means being operativein response to decreasing speeds of the transportation-device forinsuring that the aforesaid mechanical driving-means is substantiallyinoperative in response to a transportation-device speed below apredetermined value, time-delayed means, operative independently of thespeed of the mechanical load device, and delayedly responsive to asubstantially complete cessation of movement of thetransportation-device for fulfilling a condition necessary to thefunctioning of the electrical driving-means, and means, cooperating withsaid time-delayed means, for insuring a deenergization of the electricaldrivingmeans when the transportation-device barely begins to move,

5. Mechanism for driving a mechanical load device on amovabletransportation-device, comprising electrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each effectively operative only upon the fulfillment of certainpredetermined conditions, speed-responsive means responsive to the speedof the transportation-device, said speed-responsive means beingoperative in response to increasing speeds of the transportation-devicefor fulfilling a condition necessary to the functioning of themechanical driving-means in response to a transportationdevice speedabove a predetermined value, said speed-responsive means being operativein response to decreasing speeds of the transportation-device forinsuring that the aforesaid mechanical driving-means is substantiallyinoperative in response to a transportation-device speed below apredetermined value, time-delayed means, operative independently of thespeed of the mechanical load device, and delayedly responsive to asubstantially complete cessation of movement of thetransportation-device for fulfilling a condition necessary to thefunctioning of the electrical driving-means, and means responsive to apredetermined short distance of travel from standstill, substantiallyregardless of speed, and cooperating with said time-delayed means, forinsuring a deenergization of the electrical driving-means when thetransportationdevice begins to move.

6. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising electrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each effectively operative only upon the fulfillment of certainpredetermined conditions, speed-responsive means responsive to the speedof the transportation-device, said speed-responsive means beingoperative inresponse to increasing speeds of the transportation-devicefor fulfilling a condition necessary to the functioning of themechanical driving-means in response to a transportationdevice speedabove a predetermined value, said speed-responsive means being operativein response to decreasing speeds of the transportation-device forinsuring that the aforesaid mechanical driving-means is substantiallyinoperative in response to a transportation-device speed below apredetermined value time-delay means responsive to a reduction of thespeed of the transportation-device to a value below a predetermined lowminimum for thereafter interposing a time-delay sufficient, in general,for the transportation-device to come to a complete rest, and forsubsequently, after said time-delay. fulfilling a condition necessary tothe functioning of the electrical driving-means, and means for insuringa deenergization of the electrical driving-means when thetransportation-device barely begins .to move.

'I. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising electrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each effectively ope ative only upon the fulfillment of certainpredetermined conditions, speed-responsive means responsive to the speedof the transportation-device, said speed-responsive means beingoperative in response to increasing speeds of the transportation-devicefor fulfilling a condition necessary to the functioning of themechanical driving-means in response to a transportationdevice speedabove a predetermined value, said speed-responsive means being operativein response to decreasing speeds of the transportation-device forinsuring that the aforesaid menecessary to the functioning of themechanical driving-means in response to a transportationdevice speedabove said materially higher speed and for insuring that the aforesaidmechanical driving-means is substantially inoperative in response to atransportation-device speed below said materially higher speed.

10. Mechanism for driving a mechanical load device on a movabletransportation-device, comtravel from standstill, substantiallyregardless of speed, for insuring a deenergization of the electricaldriving-means when the transportationdevice begins to move.

8. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising electrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each efiectively operative only upon the fulfillment of certainpredetermined conditions, means operative at the first movement of thetransportation-device, upon starting from standstill, for insuring adeenergization of the electrical driving-means when thetransportation-device barely begins to move, time-delayed means,cooperative with said movement-responsive means substantiallyindependently of the speed of the mechanical load device, and delayedlyoperative after the transportation-device has decelerated toa very lowspeed, for fulfilling a condition necessary to the functioning of theelectrical driving-means, and means responsive to a materiallyhigherspeed of the'transportation-device for fulfilling a condition necessaryto the functioning of the mechanical driving-means in response to atransportation-device speed above said materially higher speed and forinsuring that the aforesaid mechanical driving-means is substantiallyinoperative in response to a transportation-device speed below saidmaterially higher speed.

9. Mechanism for driving a mechanical load device on a movabletransportation-device, com-- prising electrical driving-means for attimesv driving said mechanical load device, mechanical driving-meansmotivated by the movement of the transportation-device for at timesdriving said mechanical load device, said electrical and mechanicaldriving-means being each effectively operative only upon the fulfillmentof certain predetermined conditions, means operative at a very low speedof the transportation-device, upon starting from standstill, forinsuring a deenergization of the electrical driving-means when thetransportation-device begins to move, time-delay means responsive to areduction of the speed of the transportation-device to a value below apredetermined low minimum for thereafter interposing a time-delaysufllcient, in general, for the transportation-device tocome to acomplete rest, and for subsequently, after said time-delay, fulfilling acondition necessary to the functioning of the electrical driving-means,and means .re-

. sponsive to a materially higher speed of the transportation-device forfulfilling a condition prising electrical driving-means for driving saidmechanical load device when the transportationdevice is stationary,mechanical driving-means motivated by the movement of thetransportation-device for driving said mechanical load device when thetransportation-device is moving, a pair of pivoted arms, means forbiasing said arms toward normal positions, means motivated by theinitial movement of the transportation-device for alternately actuatingsaid arms, one at a time, to their actuated positions, arm-holding meansoperative to retain each arm in its actuated position once it isactuated, and means for insuring the deenergization of the electricaldrivingmeans when both of said arms are in their actuated positions atthe same time.

11. Mechanism for driving a mechanical load device on a movabletransportation-device,comprising electrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each effectively operative only upon the fulfillment of certainpredetermined conditions, and controlling-means for said electricaldriving-means, comprising a pair of pivoted arms, means for biasing saidarms toward normal positions, means motivated by the initial movement ofthe transportation-device for alternately actuating said arms, one at atime, to their actuated positions, arm-holding means operative to retaineach arm in its actuated position, once it is actuated, time-delay meansresponsive to a reduction of the speed of the transportation-device to avalue below a predetermined low minimum, and further responsive to bothof said arms being in their actuated positions, for thereafterinterposing a material timedelay and for subsequently, after saidtime-delay, releasing said arm-holding means, and means for fulfilling acondition necessary to the energization of the electrical driving-meansin response to either one of said arms being in its normal non-actuatedposition, and for insuring the deenergization of the electricaldriving-means in response to both of said arms being in their actuatedpositions.

l2. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising a storage battery, a direct-currentdynamo-electric machine operative either as a generator to charge saidbattery or as a motor energized therefrom, mechanical driving-meansbetween said mechanical load device and said electric machine,speed-responsive engageable and disengageable mechanical driving-meansmotivated by the movement 'of the transportation-device for driving boththe mechanical load device and the electric machine, reversibly movablereversing-switch means having biasingmeans for restoring the same to aneutral central position, slip-permitting actuating-means motivated bythe movement of the transportationdevice in either direction forapplying actuatingforce to said reversing-switch means depending.

in direction and amount, upon the direction and speed of movement of thetransportation-device, first and second forward-responsivecontactmechanisms actuatable at different forward displacements of saidreversing-switch means, first and second backward-responsivecontact-mechanisms actuatable at different back ward displacements ofsaid reversing-switch means,

means for reversing the field of said dynamovoltage, said secondcontact-mechanisms being actuatable at a speed of the translating devicelower than the speed at which said reverse-current means operates, andmotor-controlling means for controlling the connection of the electricmachine to the battery for motoring operation in a predetermined mannerresponsive to a non-actuated condition of both of said firstcontact-mechanisms.

13. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising a storage battery, a direct-currentdynamo-electric machine operative either as a generator to charge saidbattery or as a motor energized therefrom, mechanical driving-meansbetween said mechanical load device and said electric machine,speed-responsive engageable and disengageable mechanical driving-meansmotivated by the movement of the transportationdevice for driving boththe mechanical load device and the electric machine, reversibly movablereversing-switch means having biasingmeans for restoring the same to aneutral central position, slip-permitting actuating-means motivated bythe movement of the transportation-device in either direction forapplying actuating-force to said reversing-switch means depending, indirection and amount, upon the direction and speed of movement of thetransportation-device, first and second forward-responsivecontact-mechanisms actuatable at different forward displacements of saidreversing-switch means, first and second backward-responsivecontact-mechanisms actuatable at different backward displacements ofsaid reversing-switch means, means for reversing the field of saiddynamo-electric machine in accordance with which of said secondcontact-mechanisms was last actuated, reverse-current means forconnecting and disconnecting said electric machine to and from thebattery to control the generator-operation of said machine in accordancewith its senerated voltage, said second contact-mechanisms beingactuatable at a speed of the translating non-actuated condition of bothof said first contact-mechanisms, and further responsive to both of saidarms being in their actuated positions, for thereafter interposing amaterial time-delay and for subsequently, after said time-delay,releasing said arm-holding means, and means for fulfilling a conditionnecessary to the energiza-tion of the electric machine as a motor, inresponse to either one of said arms being in its normal non-actuatedposition, and for insuring the deenergization of the electric machine asa motorin response to both of said arms being in their actuatedpositions.

14. Mechanism for driving a mechanical load device on a movabletransportation-device, comprising electrical driving-means for at timesdriving said mechanical load device, mechanical driving-means motivatedby the movement of the transportation-device for at times driving saidmechanical load device, said electrical and mechanical driving-meansbeing each effectively operative only upon the fulfillment of certainpredetermined conditions, speed-responsive means responsive to the speedof the transportationdevice, said speed-responsive means being operativein response to increasing speeds of the transportation-device forfulfilling 'a condition necessary to the functioning of the mechanicaldriving-means in response to a transportationdevice speed above apredetermined value, said speed-responsive means being operative inresponse to decreasing speeds of the transportation-device for insuringthat the aforesaid mechanical driving-means is substantially inoperativein response to a transportation-device speed below a predeterminedvalue, said electrical driving-means comprising a storage battery, adirectcurrent dynamo-electric machine, a double-duty maincontactor-switch for connecting and disconnecting said dynamo-electricmachine to and from the battery for both motoring and generatingoperation, mechanical driving-means motivated by the movement of thetransportationdevice for at times driving said dynamo-electric machine,a reverse-current switch for fulfilling a condition necessary to theclosure of said main contactor-switch in response to an operationalcondition which qualifies the dynamo-electric machine to charge saidbattery and for effecting the opening of said main contactor-switch inresponse to an operational condition which disqualifies thedynamo-electric machine from charging said battery, means sointerrelated to the decreasing-speed response of said speed-responsivemeans as to be operative only subsequently thereto in response todecreasing speeds of the transportation-device for fulfilling acondition necessary to the closure of said main contactor-switch,movement-responsive means for insuring an opening of said maincontactorswitch when the transportation-device barely begins to move,and time-delayed means, operative independently of the speed of themechanical load device, for delayedly resetting said movement-responsivemeans to its non-responsive position after a cessation of movement ofthe transportation device.

WALTER H. SMITH.

